Closed centrifugal separator



Feb. 1, 193.8. s. H.-HAL| CLOSED CENTRFUGAL SEPARATOR Filed Jam-2s, 1955 J m F Il ...l

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Patented Feb. l, 1938l UNITED STATES 4PATENT OFFICE j l 2,107,035 l cross cEN'raxFUGAL Seminaren semen n. nan, Poughkeepsie, N. Y., assignmto The Dc Laval Separator Company, New York, N. Y., a' corporation of New Jersey Application January 23, 1935, Serial No. 3,089

In Sweden February 16, 1934 2 (llaims.`

The liquid must often be passed under rather' high pressure through these latter apparatus. The special tightening devices which must be arranged in hermetic separators cannot,- however, as a rule stand up to more than a given pressure. In case one or more apparatus are to be coupled in series it is therefore necessary to interpose pumps between the separator and the said apparatus in order to reduce the load on the stufiing box at the inlet of the separator.

According to the present invention centrifugal pump wheels or pump impellers, carried by the `bowl spindle or otherwise arranged to rotate with the bowl, are located directly on the inlet and/or the outlet of the separator, In this way several considerable advantages are attained. The packing at the inlet canl be wholly or partly freed of any load, and pump wheels of the type referred to are more advantageous in several respects than common pumps. The dimensions of the wheels. can be small owing to the generally high number. of revolutions, which means higher eiect and'more convenient cleaning. Besides, a considerable simplification of the whole installation is possible, as both the motor and the driving arrangements may be combined with the separator.

'I'he accompanying drawing illustrates several embodiments of the invention.L

Fig. 1 is an external view of a centrifugal separator having the inlet located at the lower part of the separator vandthe outlets vat the upper part. Fig. 2 is a vertical sectional view of the upper part o f the separator of Fig. 1, showing the two outlets and centrifugal pump impellers, functioning as pressure generators, arranged to rotate with th separator and positioned at the outlets.

Fig. 3 is a vertical sectional view of the lower part of a separator provided with an inlet at -th'e bottom and a centrifugal pump, functioning as' a pressure generator; arranged to rotate with the driving spindle and positioned at the inlet.

Fig. 4 is a detail view in vertical section of the preferred construction of the lower (inlet) end of the separator of Figure 1 when the pressure generator is applied at one or both of the outlets 'and not at the inlet. l

Referring to Figs. 1 and 2 and more particu# larly to Fig. 2: l is. the centrifugal separator having a hollow spindle or tube 5 forming an outlet communicating with the central part of the separating space of the bowl and (surrounding pipe 5) an outlet tube or neck 4 forming an annular passage i communicating with the peripheral part of the separating space of the bowl. Fixed pipes 2 and 3 communicate respectively with tubes 5 and 4 and are made tight'by ilexible packings 8. Secured to the tubes 5 and 4i, which lrotate with the bowl, is a centrifugal pump wheel 6, which is preferably made removable, through which the heavy liquid discharged through tube d must pass on its way to the fixed outlet pipe '3. The ldescribed construction is designed for use where apparatus, such as a pasteurizer. connects only with the pipe 3;l but if a similar apparatus connects, also or instead, with pipe 2, it may be desirable, in exceptional cases, to plac'e a similar centrifugal pump wheel Ell, also or instead, at the upper end of tube 5. The centrifugal pump wheel in either position hasthe great advantage that it supplies force to y overcome the back pressure on the outlet Without requiring excessive pressure on the packing I8 shown in Figs. 3 and 4 at the inlet.

If the throughput of the separator is very high, an increased pressure on the separated liquid is necessary at the inlet. .At and over' a.

.given throughput I therefore provide a centrifu- -gal pump wheel at the inlet, as shown in Fig. 3.

The pump wheel I0 is here xed to the bored spindle 1 and is surrounded by a xed casing member 8a, enclosing a passage communicating `with a pipe Il. through which the liquid to be separated ows to the pump wheel, and a xed casing member 9b which, with vthe AcasingA member 9a, encloses a chamber I6 through which the liquid to be separated flows from the pump wheel I1, so that no additional sealing devices are necessaryother than the narrow clearances genl erally used in centrifugal.A pumps. By the delscribed arrangement it is possible to construct hermetically closed separators even for very high throughputs. A

Within chamber I8 are placed one or more wings Il, which may extend radially, and which act to reduct the rotative speed oi the liquid during its ilow from the pump wheel toward the hollow spindle.

In the arrangement shown in Fig. 3 the suction side of the pump is `turned from the inlet of the spindle, thereby imposing a minimum load on the sealing device I8.

For the centrifugal pump wheel shown may be substitutedany other known equivalent device which, when applied to a rapidly rotating member, will generate pressure in a liquid flow passage, Y

but the centrifugal pump wheel has certain 'ad- -vantagesover other types of pressure generators.

What I claim and desire to protect by Letters pumped from the ilr'st mentioned chamber to the second mentioned chamber, and guiding wings positioned in the second mentionedchamber and adapted to reduce the rotative speed of the liquid during its ilow from the pump impeller to the l hollow spindle.

2. A centrifugal separating apparatus comprising a xed inlet pipe, ilxed outlet pipes, a rotatable centrifugal separator having outlets in closed communication with the iixed outlet pipes respectively, a hollow spindle rotating with the separator and through which liquid to be separated is adapted to ow to the separator, casing members providing a stationary chamber communieating with the fixed inlet pipe and through which lsaid spindle passes and a second stationary chamber below said first chamber and communicating with the inlet end of said rotatable hollow spindle, ilexible means to seal the joint between said spindle and the wall of said ilrst chamber, and a centrifugal pump impeller mounted on said spindle and through which inflowing liquid is pumped from said rst chamber to said second chamber whereby the sealing means is subjected only to the low pressure obtaining on the suction side of said centrifugal pump impeller.

' SELDEN H. HALL. 

